Drug abuse with its potential for drug overdose poisonings, both accidental and intentional, is a major national health problem which is rapidly on the rise. Contributing factors for this increase are both economic (eg. unemployment) and more importantly from a long term standpoint, the rapid increase in the number of prescriptions written for drugs of abuse (eg. analgesics and psychopharmacologic agents) and the rapid rise in the national geriatric population. Health care professionals have recognized for a long time the need for rapid analytical methods for determining which class of drug or drugs are present in an emergency situation. The Public Health Service realizes the seriousness of this problem and has requested small business innovative research proposals under the auspices of the Alcohol, Drug Abuse, and Mental Health Administration. Numerous methods are available for determining drug levels in biological fluids but all must be performed in a laboratory environment. Most of the available assays require expensive equipment, trained personnel, and are slow in determining which drug is present. Use of radioimmunoassay (RIA) procedures the additional problem of radioactive waste disposal which is presently, and will increasingly become a major problem in the future. We propose to develop a homogeneous dip strip enzyme immunoassay which will be useful for emergency situation determination of which class of drug or drugs was taken in overdose. The assay is expected to be simple, fast (less than 10 minutes), noninstrumental, and thus easily portable for use by emergency personnel at the scene of the suspected overdose. This procedure will determine which drug class is present and thus allow for general supportive measures prior to arrival at medical facilities.